1. Field of the Invention
The present invention relates to holders for loose leaf sheets of material, and more particularly to those which provide a convenient means for insertion and removal of the sheets and a firm base upon which to write or draw.
2. Description of the Prior Art
The most common loose leaf folders or binders for paper are of the type having hinged covers, and a back panel to join the two. Located between the cover and base along the inside of the back panel are metal or plastic rings constructed and joined in a manner which allows the user to "open" the rings simultaneously into a U-shaped position. A leg of each of the now U-shaped rings is passed through a pre-punched hole in a loose sheet of paper. Once the paper is retained upon the legs, the opened rings are closed shut by the user and the paper remains in the holder until the user reverses the above-described process.
Although in general, these devices have performed satisfactorily there are some problems which include painful injury to the user's hand when a ring catches the skin of the hand as the ring snaps shut and inconvenience to the user when the rings prohibit the user from writing to the edge of the paper due to the user's writing-hand knuckles hitting against the rings as the edge of the paper is reached. Also, as the amount of paper to be contained increases, the retaining rings must be made substantially larger to adequately hold the paper. The increased size of the rings requires that the holder become cumbersome in weight and bulky in appearance. Furthermore, if the paper happens to slip off either one or all of the rings, it can cause quite an inconvenience to the user to place it back upon the rings when the folder is full and the loosened sheet is not the top sheet.
Another conventional holder which has some pitfalls is that utilizing a clip board retaining device. Such a device, though, is generally incapable of holding more than a thin layer of sheets without the lower sheets slipping free. Also, the sheets of the top layers of the stack often times get creased by the clamping force of the clip.
The present invention utilizing a magnetic body and magnetically-responsive material can provide a solution to the above-described problems.